#include<stdio.h> 

int main(){
	void swap(int* a, int*b);
	
	int a = 1, b = 2;
	
	swap(&a, &b);
	printf("a = %d, b = %d", a, b);
}

void swap(int* p, int* q){
	int temp;
	temp = *p;
	*p = *q;
	*q = temp;
}
